Imaging elements using organic semiconductor materials for photoelectric conversion layers can photoelectrically convert specific colors (wavelength bands). Furthermore, due to the characteristic, in the case of using the imaging elements as imaging elements in solid-state imaging devices, it is possible to achieve a structure (stacked-type imaging element) of sub pixels where each subpixel is configured as a combination of an on-chip color filter (OCCF) and an imaging element, and the subpixels are arranged two-dimensionally (for example, refer to JP 2011-138927 A). In addition, since a demosaic process is not necessary, there is an advantage in that false color does not occur. Note that, in the description hereinafter, in some cases, an imaging element which is provided on or above a semiconductor substrate and includes a photoelectric conversion unit is, for the convenience of description, referred to as a “first-type imaging element;” a photoelectric conversion unit constituting the first-type imaging element is, for the convenience of description, referred to as a “first-type photoelectric conversion unit;” an imaging element provided in a semiconductor substrate is, for the convenience of description, referred to as a “second-type imaging element;” and a photoelectric conversion unit constituting the second-type imaging element is, for the convenience of description, referred to as a “second-type photoelectric conversion unit.”
A structure example of a stacked-type imaging element (stacked-type solid-state imaging device) in the related art is illustrated in FIG. 49. In the example illustrated in FIG. 49, a third photoelectric conversion unit 331 and a second photoelectric conversion unit 321 are second-type photoelectric conversion units constituting a third imaging element 330 and a second imaging element 320, respectively, as second-type imaging elements that are formed in a semiconductor substrate 370 to be stacked. In addition, a first photoelectric conversion unit 311 is a first-type photoelectric conversion unit arranged above the semiconductor substrate 370 (specifically, above the second imaging element 320). The first photoelectric conversion unit 311 is configured to include a first electrode 311, a photoelectric conversion layer 315 made of an organic material, and a second electrode 316 and constitutes a first imaging element 310 as a first-type imaging element. Due to a difference in the absorption coefficient, the second photoelectric conversion unit 321 and the third photoelectric conversion unit 331 photoelectrically convert, for example, blue light and red light, respectively. In addition, the first photoelectric conversion unit 311 photoelectrically converts, for example, green light.
Charges generated through photoelectric conversion in the second photoelectric conversion unit 321 and the third photoelectric conversion unit 331 are temporarily stored in the second photoelectric conversion unit 321 and the third photoelectric conversion unit 331 and, after that, are transferred to the second floating diffusion layer (Floating Diffusion) FD2 and the third floating diffusion layer FD3 by a vertical-type transistor (gate portion 322 is illustrated) and a transfer transistor (gate portion 332 is illustrated), respectively. The charges are further output to an external reading circuit (not shown). The transistors and the floating diffusion layers FD2 and FD3 are also formed in the semiconductor substrate 370.
Charges generated through photoelectric conversion in the first photoelectric conversion unit 311 are stored through a contact hole portion 361 and a wire line layer 362 to a first floating diffusion layer FD1 formed in the semiconductor substrate 370. The first photoelectric conversion unit 311 is also connected through the contact hole portion 361 and the wire line layer 362 to a gate portion 318 of an amplification transistor which converts a charge amount to a voltage. Furthermore, the first floating diffusion layer FD1 constitutes a portion of a reset transistor (gate portion 317 is illustrated). Note that reference numeral 371 denotes an element isolation region; reference numeral 372 denotes an oxide film formed on a surface of the semiconductor substrate 370; reference numerals 376 and 381 denote interlayer insulating layers; reference numeral 383 denotes a protective layer; and reference numeral 390 denotes an on-chip microlens.